Neoclassical realism is one of the major new developments in realist theory in the past two decades, and provides a theoretical framework, whether explicit (Boyle, Chapter 4) or implicit (Bano, Chapter 5) for two of the chapters in this volume. It is an approach that aspires to bridge the gap between classical realism's focus on foreign policy and neorealism's systematism and parsimony. Rather than classical realism's focus on policy prescription, neoclassical realism looks to explain foreign policy, and to do so by using neorealism's conclusions about the nature of anarchy and the international system as a starting point. But to the extent that it espouses a neopositivist methodology, as most neoclassical realists do, it fails. This methodology, which assumes that specific policy predictions can be derived from neorealism and claims to be using specific cases to generate broader inferences about foreign policy making, is inappropriate to its goal of explaining foreign policy decisions.

In practice, the absence of fit between explanatory goal and espoused methodology has meant that for the most part the methodological claims of neoclassical realists are not matched by the methods they use. Jennifer Sterling-Folker, for example, notes that ‘realist structural expectations are so broad that most of the heavy explanatory lifting must be done by constructivism instead, which is why neoclassical realist scholarship typically produces historical narratives’ (Sterling-Folker 2009a, p. 111). This chapter expands on and unpacks her observation. It argues that constructivism, which assumes that international politics are socially constructed rather than determined by a distribution of material capabilities, and which therefore focuses on the norms, identities, discourses, and so on that inform foreign policy decision making, provides the appropriate set of methodologies for neoclassical realism.

Matching their generally implicit constructivist methods with explicitly constructivist ontologies and methodologies would allow neoclassical realists to broaden the scope of cases they can usefully discuss, to better address questions of power in the making of foreign policy, and to deal effectively with the belief structures that so often underlie foreign policy. It would also, contra neopositivist claims to science by many neoclassical realists, improve the explanatory robustness of the approach by moving the focus of debate from discussions about neorealism and foreign policy that cannot be decided empirically to discussions of specific foreign policy contexts that are based on empirical analysis.